June 9, 1923 
Rogue Types in Garden Peas 
825 
The F2 hybrids differ from the generation in being remarkably 
like the pure rogues at all stages in their development. The stipules at 
the fourth, fifth, and sixth nodes of the former are especially different 
from those of the F^ plants. The measurements serve to emphasize 
what is plainly seen by inspection of the cultures, namely, that the Fj 
seedlings resemble the pure rogues of the same age rather than the young 
Fj plants which so generally exhibit a typelike character: To the eye, 
neither of the hybrid generations, at maturity, differs in any appreciable 
way from the rogue parent. 
Besides measuring the stipules at the fourth to the ninth nodes in the 
case of the rogue, type, and F^ and Fj hybrids, measurements were made 
of four stipules per plant from about the eighth to the fourteenth node 
of mature individuals in each category. The mature plants measured 
included those used in the comparison by nodes of the four groups, and, 
in the case of all but the F^ hybrids, additional plants were measured. 
In Table VII are shown the frequency distributions and statistical 
constants calculated for each of the four categories of plants. The range 
of variation is strikingly significant, the range of the type not overlapping 
that of the rogue. The F^ and F2 hybrids have a range of variation equal 
in extent to that of the rogue parent. The F2 generation differs from the 
pure rogue and the F^ in that it is less variable as indicated by the co¬ 
efficients of variation (Coefficient Variation): F2 generation, 5.84 ±0.2677; 
rogue, 7.06 ±0.2912; Fj generation, 7.09 ± 0.3662, respectively. The prob¬ 
able errors of the differences between the coefficients of variation of the 
pure rogue and of the F2, and of the F2and F^, are practically three times 
the difference, in each case indicating that the differences are real. How¬ 
ever, the differences in variability of the three groups as shown by the 
stipule measurements of the mature plant were not apparent on inspection 
of the cultures. 
The resemblance of the F^ and F2 hybrids to the pure rogues is further 
accentuated by a comparison of the mean stipule ratio of the three. 
The mean for the rogue parent is 2.339 ±0.0096; for the Fj, 2.383 ±0.0196; 
and for the F2 it is 2.360±0.0089. There is no significant difference 
between any of the three means. 
Thus in regard to variability, range of variation, and mean stipule 
ratio, the two hybrid generations resemble only the rogue parent. 
The influence of the type parent, in crosses between type and rogue is 
apparent only in the F^ plant and at only the lower nodes. 
CROSSES BETWEEN THE GRADUS STRAIN AND MUMMY, A NONROGUE- 
PRODUCING VARIETY. 
In 1918 the English “Mummy” pea was used in crosses with Gradus 
rogue and Gradus type. Seed of the Mummy variety was first obtained 
from O. E. White of the Brooklyn Botanical Garden (White’s No. 
Pi-3-4-2), and only this strain has been used in the crosses. In Mummy, 
fasciation of the main stem is characteristic, but does not appear until 
the plant is well developed. With the appearance of the fasciated 
condition the stipules become narrower and more pointed than those 
at the lower and middle nodes of the same plant. Plate 2, A, B, C is 
of a mature plant of Mummy. Although having stipules much narrower 
than in Gradus type, no rogue comparable to those found in Gradus 
have ever been observed by the writer among the several thousand 
